Vulnerability Description
cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Davegamble | Cjson | <= 1.7.19 |
Related Weaknesses (CWE)
References
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180Patch
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploitPress/Media CoverageThird Party Advisory
- https://www.vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-Third Party Advisory
FAQ
What is CVE-2026-67216?
CVE-2026-67216 is a vulnerability with a CVSS score of 5.9 (MEDIUM). cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with ...
How severe is CVE-2026-67216?
CVE-2026-67216 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-67216?
Check the references section above for vendor advisories and patch information. Affected products include: Davegamble Cjson.